About this replacement
Symbol MC35 Series — 3.7V Li-ion Replacement Battery (BTRY-MC35EABOE)
This is a 3.7V, 2650mAh Li-ion battery for the Symbol MC35 handheld mobile computer. It fits the MC35, MC3504, MC3574, and MC35-C-E5B2 — the same pack across the series. It slots directly into the battery compartment and communicates with the device BMS the same way the original does.
- MC35 series compatibility: The MC3504, MC3574, and MC35-C-E5B2 all share the same 3.7V battery bay, connector pinout, and BMS handshake protocol. One pack covers the whole lineup without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the MC35 platform. The BMS accepted the cell, reported state-of-charge correctly in the device menu, and showed no fault flags across the test sequence.
- First-shift prep for pick-and-pack: Place the scanner in its cradle for a full charge cycle before the first use. Scan-trigger inrush current peaks when the cell is near minimum — a fully charged pack prevents false BMS trips when the first shift hits high-volume scanning right out of the gate.
Cradle showing a charging error on a new pack
A charging error on a brand-new pack is almost always a contact resistance issue, not a faulty battery. The MC35 cradle uses spring-loaded dock contacts that collect dust, label residue, and warehouse grime quickly. High contact resistance causes the charger circuit to read a voltage anomaly and flag an error. Wipe the gold contacts on both the battery and the cradle with a dry cloth, reseat the pack firmly, and the charge cycle should start normally.
Scanner losing wireless connection during rapid scan bursts
The MC35 draws from the same cell for both the wireless radio and the scan trigger. During fast scan sequences, the combined inrush from the imager firing and the radio transmitting simultaneously pulls a spike of current that a degraded or partially charged cell can't sustain cleanly. The BMS clamps the output to protect the cell, and the radio drops first because the scanner prioritises the imager. Start each shift with a fully charged pack — if dropouts continue on a charged cell, check that the battery contacts are clean and seated flush.